Cynodontidae

From The Aquarium Wiki

Cynodontidae, or Dogtooth Characins, are a family of freshwater fishes found in the Neotropics. They belong to the order Characiformes, the family is not very diverse with only 5 genera and 14 species. They have a very peculiar shape, and their name derives from their elongated and well developed canines which they mainly use to eat other fish. Their pectoral fins are also expanded. The maximum length reached is 65 cm.